This U.S. Geological Survey charts shows the actual level of water flow at the mouth of the Souhegan River since the start of February (the blue line) compared to the historic average for each day (the line of triangles). Note that the vertical scale is not linear.

U.S. Geological Survey map shows streamflow levels in March. The Connecticut River watershed is in good shape, but the Merrimack River watershed (the organe color) is below average, as are some watersheds further north.

STAFF PHOTO BY BOB HAMMERSTROM

A lack of rain meant water levels were low on area rivers including the Souhegan in Milford, Tuesday, April 3, 2012.

Water levels at record lows

By DAVID BROOKS

Staff Writer

Gone kayaking on the upper Souhegan River lately?

Don’t bother. There isn’t enough water.

“Only a couple of rivers in New Hampshire are at a runnable level,” said Paul Berry of Merrimack, part of the New Hampshire Appalachian Mountain Club Paddlers group. “Whitewater school starts the weekend after this, and right now I’m kind of scrambling to figure where we’re going to end up having enough water.”

It’s not that the rivers are bone dry, it’s just that they’re dry for what is normally a wet time of year. Last year in early April, for example, The Telegraph cautioned that early spring flooding had made rivers dangerous.

On Tuesday, flow at a U.S. Geological Survey gauge at the mouth of Souhegan River was just 180 cubic feet per second, lower than it has been for 96.5 percent of the time since records began being kept some 77 years ago.

The river flow was one-third lower in Milford, where a second real-time gauge is maintained by the USGS, although it’s unclear how that fits into historical patterns because the gauge is fairly new.

Down in Pepperell, Mass., the Nashua River’s flow was lower than it has been for 95 percent of historical records.

Even the Merrimack River is flowing slowly – at 3 percent of the historic average in Manchester, 2 percent in Lowell. The Merrimack River looks quite high because the level is controlled by dams.

The problem is a dry winter that saw record-low levels of snow, meaning there’s no melting snowpack to fill creek banks.

That was compounded by warm weather, which has dried out the ground and led trees to produce buds and leaves earlier than usual. Plants pull large amounts of water out of the ground when they’re growing.

“Evapotranspiration will happen for a longer period – more water use by vegetation could compound the situation,” said Richard Kiah, chief of hydrologic network operations for USGS in Pembroke.

“There was no snowpack, there isn’t a whole lot of moisture in the ground, there hasn’t been a whole lot of rain. Put all that together and it’s a problem,” said Berry.

This isn’t unprecedented, but it is worrisome.

“In 2006, March and April had a similar drop in river levels, then we had a wet period following that,” said Kiah. “It’s all depending on if this weather pattern holds.”

No rain is forecast until early next week.

The dryness is already showing up in terms of brush fires. The state called a Class 4 Fire Danger Day on Tuesday, an unusually high level of danger for this early in the year.

Still, it could be worse – and further south, it is.

Eastern Massachusetts, Rhode Island and parts of Connecticut are already in drought situations. Blue Hill Meteorological Observatory has measured less precipitation so far this year than any year since record keeping began in 1886.

Slightly west of here, however, things are different. The Connecticut River valley is in fine shape, partly because of high runoff from the Vermont side of the border.

As far as water supplies go, that’s mostly a function of groundwater, particularly since almost half the homes in Greater Nashua develop on private wells.

So far, according to USGS, monitoring wells near Exit 8 of the F.E. Everett Turnpike and in the towns of Hooksett and Greenfield, groundwater levels are normal. It can take weeks or more for changes in surface water levels to percolate down and affect groundwater levels.

As for paddling prognostication, Berry remains hopeful.

“There have been times when we’ve had little snowpack, but then did get some heavy spring rains,” he said. “My fingers are crossed.”

David Brooks can be reached at 594-6531 or dbrooks@nashuatelegraph.com.